System and method for intervertebral implant delivery and removal

ABSTRACT

An implant system provides motion preservation or stabilization between two spinal vertebrae. An associated instrumentation system is capable of delivering and removing the implants from either the anterior, left lateral or right lateral positions. The instrumentation system also provides instrumentation for delivering the implant end plates into the disc space, adjusting the position of the end plates in situ, compressing end plates into the vertebral bodies, interoperatively determining the height and angulation of bearings, delivering bearings together and then independently connecting them to the end plates. The system provides alternative instrumentation for revising the motion preservation disc from at least three directions. The system further provides alternative instrumentation for converting the motion preservation disc system to an interbody fusion device from at least three directions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the following:

U.S. Provisional Application No. 60,720,513, filed Sep. 26, 2005, whichcarries Applicants' Docket No. MLI-45 PROV and is entitled MODULARARTICULATING AND FUSION SPINAL DISC IMPLANT SYSTEM;

U.S. Provisional Application No. 60/720,514, filed Sep. 26, 2005, whichcarries Applicants' Docket No. MLI-46 PROV and is entitled UNIVERSALSPINAL DISC IMPLANT SYSTEM FOR PROVIDING INTERVERTEBRAL ARTICULATION ANDFUSION; and

U.S. Provisional Application No. 60/741,513, filed Nov. 30, 2005, whichcarries Applicants' Docket No. MLI-50 PROV and is entitled SYSTEM ANDMETHOD FOR INTERVERTEBRAL IMPLANT DELIVERY AND REMOVAL.

All of the foregoing are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. The Field of the Invention

The present invention relates generally to spinal orthopedics, and moreprecisely, to intervertebral implants and related instrumentation.

2. The Relevant Technology

Severe back pain can be caused by sa number of different ailments,including spinal stenosis, degenerative disc disease, spondylolisthesis,and the like. Many such ailments can be corrected by controlling orlimiting relative motion between the affected vertebrae. Accordingly, avariety of devices including artificial discs and fusion devices havebeen proposed.

A variety of instruments have also been proposed for use with suchintervertebral devices. These instruments are typically limited to usewith one implant configuration and/or one surgical approach.Accordingly, many known instruments are usable only when the indicationsfit within a relatively narrow set of criteria. Furthermore, the softtissue damage often caused by operation in the intervertebral disc spacemay prevent any revision surgery from being carried out along the sameapproach. Thus, many known instruments are not usable for revision of anexisting intervertebral treatment.

Further, many known instruments are expensive or difficult tomanufacture, or are difficult to use. Accordingly, there is a need inthe art for instrumentation that remedies these problems.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present invention will now be discussed withreference to the appended drawings. It is appreciated that thesedrawings depict only typical embodiments of the invention and aretherefore not to be considered limiting of its scope.

FIG. 1 is a perspective view of an intervertebral disc motionpreservation implant in an assembled state.

FIG. 2 is a perspective view of an adjustable support assembly, a pivotassembly, and an end plate instrument assembly.

FIG. 3 is a perspective view of a bearing instrument assembly and thepivot assembly shown in FIG. 2, and the implant shown in FIG. 1.

FIG. 4 is a top elevation view of the pivot assembly shown in FIG. 2.

FIG. 5 is a perspective view of the end plate instrument assembly andthe pivot assembly shown in FIG. 2, and two end plates.

FIG. 6 is a perspective view of the pivot assembly shown in FIG. 2 andtwo end plate holders.

FIG. 7 is a side elevation view of the pivot assembly and end plateholders shown in FIG. 6, with hidden parts shown in phantom.

FIG. 8 is a side elevation view of the distal end of an end plate holdershown in FIG. 6 and an end plate, with hidden parts shown in phantom.

FIG. 9 is a side elevation view of the distal end of a spike guard.

FIG. 10 is a side elevation view of the distal end of the spike guardshown in FIG. 9 mounted on an end plate.

FIG. 11 is a perspective view of the distal end a primary spacer.

FIG. 12 is a side elevation view of the end plate instrument assemblyshown in FIG. 5, and two end plates.

FIG. 13 is a perspective view of an intervertebral disc motionpreservation implant in a disassembled state.

FIG. 14 is a perspective view of the distal end of a secondary spacer.

FIG. 15 is a side elevation view of the distal end of two end plateholders and end plates shown in FIG. 8, and two primary spacers shown inFIG. 12, and two secondary spacers shown in FIG. 14.

FIG. 16 is a perspective view of the distal end of an angle compressorand an end plate.

FIG. 17 is a perspective view of the distal end of a bearing holder.

FIG. 18 is a perspective view of the distal end of the bearing holdershown in FIG. 17, attached to the superior bearing and the inferiorbearing shown in FIG. 13.

FIG. 19 is a perspective view of the distal end of a height compressor.

FIG. 20 is a perspective view of the distal end of the bearing holderand bearings shown in FIG. 18, attached to the height compressor shownin FIG. 19.

FIG. 21 is a side elevation view of the distal end of the bearinginstrument assembly and implant shown in FIG. 3.

FIG. 22 is a perspective view of an alternative bearing guidanceassembly, the support assembly, the pivot assembly and the end plateassembly.

FIG. 23 is an enlarged exploded view an alternative disc motionpreservation implant.

FIG. 24 is a perspective view of a bearing holder, holding the bearingcomponents of the implant of FIG. 23.

FIG. 25 is an enlarged view of an inferior side of a distal end of thebearing holder of FIG. 24.

FIG. 26 is an enlarged view of a superior side of the distal end of thebearing holder of FIG. 24.

FIG. 27 is an enlarged view of a superior and an inferior bearingmounted on the distal end of the bearing holder.

FIG. 28 is an enlarged view of the bearing holder with mounted bearingsinserted in the end plate assembly.

FIG. 29 is a perspective view of a compressor.

FIG. 30 is an enlarged view of the distal end of the compressor of FIG.29.

FIG. 31 is a perspective view of a superior feeler gauge.

FIG. 32 is a perspective view of an inferior feeler gauge.

FIG. 33 is a perspective view of a fusion block attached to the distalend of the bearing holder of FIG. 24.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates an intervertebral disc motion preservation implant14. The implant 14 is designed for placement between spinal vertebrae toreplace degenerated intervertebral disc material. The implant 14comprises two end plates 300, a superior bearing 800, and an inferiorbearing 850, and two snap fasteners 900. The end plates 300 areimplanted in the vertebral bodies, and the snap fasteners 900 hold thebearings 800, 850 in place between the end plates 300.

Referring to FIG. 2, a perspective view illustrates two end plates 300and an end plate instrument assembly 16 necessary to hold and guide theend plates 300 during the implantation process. Also shown are a pivotassembly 18 which holds and adjusts the end plate instrument assembly16, and an adjustable support assembly 12 which holds the pivot assembly18. The end plates 300 and the other implant components may be implantedand removed from any one of three approaches: anterior, left lateral orright lateral. Prior to the implantation procedure, the adjustablesupport assembly 12 is attached to the operating table on the right orleft side, depending upon which approach is to be used.

After the end plates 300 are implanted, the inferior 850 and superiorbearing 800 are inserted between the end plates. FIG. 3 illustrates abearing instrument assembly 17 required to insert the bearings. Thebearing instrument assembly 17 is supported by the pivot assembly 18,which in turn is held by the adjustable support assembly 12.

The instrumentation illustrated herein is for an implant 14 which has aspecific anterior-posterior angle. Implants of differing angulation maybe implanted and may require a different configuration ofinstrumentation. That is, instruments of varying sizes and designs maybe necessary to implant an implant of a wider or narrower angle. Inaddition, the order of the procedure described herein may vary for adifferent implant.

FIG. 4 depicts the pivot assembly 18. The pivot assembly 18 comprises anangle adjustment pivot 100 and a height adjustment pivot 140. The pivots100, 140 are generally U-shaped and are secured together by two screws102. The height adjustment pivot 140 has a body 150 and two arms 152which extend perpendicularly away from the body 150 and parallel to oneanother, forming a U-shape. The angle adjustment pivot 100 also has abody 110 and two arms 112 which form a U-shape. A support feature in theform of support assembly ball 114 is located on the outer side of eachangle adjustment pivot arm 112. The adjustable support assembly 12depicted in FIG. 2 attaches to the pivot assembly 113 via one of thesupport assembly balls 114. Which support assembly ball 114 is used isdetermined by the surgical approach (anterior, right lateral, or leftlateral) and the preference of the surgical personnel.

An angle adjustment guide arm 116 extends through in opening in the body110 of the angle adjustment pivot 100. At the proximal end 118 of theguide arm 116 is an angle adjustment screw 120. This angle adjustmentscrew 120 extends through the length of the guide arm 116 and emerges atthe distal end 122 of the guide arm 116, and is capped by an adjustmentnut 124. An angle adjustment gauge 130 appears as a series of numbers onthe top side of the body 110. Also on the top side of the body 110, anadjustment knob 126 extends through an opening in the body 110 to thetop of the angle adjustment guide arm 116. Tightening the adjustmentknob 126 secures the angle adjustment guide arm 116 in place within theangle adjustment pivot 100. A row of angle guide arm teeth 128 line thedistal end 122 of the angle adjustment guide arm 116.

A height adjustment guide arm 156 extends through an opening in the body150 of the height adjustment pivot 140. At the proximal end 158 of theguide arm 156 is a height adjustment screw 160. This height adjustmentscrew 160 extends through the length of the guide arm 156 and emerges atthe distal end 162 of the guide arm 156, and is capped by an adjustmentnut 164. A height adjustment gauge 170 appears as a series of numbers onthe top side of the body 150. Also on the top side of the body 150, anadjustment knob 166 extends through an opening in the body 150 to thetop of the height adjustment guide arm 156. Tightening the adjustmentknob 166 secures the height adjustment guide arm 156 in place within theheight adjustment pivot 140. A row of height guide arm teeth 168 linethe distal end 162 of the height adjustment guide arm 156.

The instrument assembly 16 and pivot assembly 18 are depicted in FIG. 5.Individual components of the instrument assembly 16 are positioned,implemented, and removed throughout the implantation procedure. In theembodiment depicted, the instrument assembly 16 consists of two endplate holders 200, two spike guards 400, and two primary spacers 500.Attached to the distal end of the end plate holders 200 are two endplates 300. (Additional spacers not depicted in FIG. 5 are used in theprocedure and will be illustrated and described as they are used.)

FIG. 6 depicts a top-down view of the pivot assembly 18 and itsconnection to the end plate holders 200. The two end plate holders 200are identical to one another; they differ only in orientation during theimplantation procedure. Each end plate holder 200 has a distal first end250 and a proximal second end 260, connected by a shaft 201. At thesecond end 260 of each end plate holder 200 is a connector 240 with anopening 242 and a plurality of connector teeth 248. One end plate holderis connected to the height adjustment guide arm 156 by fitting theopening 242 over the adjustment nut 164, and meshing the connector teeth248 with the height guide arm teeth 168. The other end plate holder 200is connected to the angle adjustment guide arm 116 in an identicalmanner; by fitting the opening 242 over the adjustment nut 124, andmeshing the connector teeth 248 with the angle guide arm teeth 128. Oncethe end plate holders 200 are connected to the adjustable guide arms116, 156, the height of the end plate holders 200 can be adjusted byturning the height adjustment screw 160, and the angle of the end plateholders 200 can be adjusted by turning the angle adjustment: screw 120.

A transparent side view of the proximal end of the end plate holders 200and the guide arms 116, 156 is shown in FIG. 7. Fitted into alongitudinal channel 210 in each shaft 201 is a spreader 220. Thespreaders 220 lie on the inside planes of the end plate holders 200 suchthat the spreaders 220 face one another once the end plate holders 200are secured to the adjustment arms 116, 156. Each spreader 220 has alever 222 which lies on the outside of the end plate holder 200. A rod226 and lever pin 224 assembly connect the spreader 220 to the lever222. When the lever 222 is in the lowered position as in FIG. 5, thespreader 220 is extended distally down the channel 210 of the shaft 201.

An end plate 300 and its connection to the first end 250 of the endplate holder 200 are illustrated in FIG. 8. The end plate 300 has aright lateral end 302, a left lateral end 304, an anterior end 306 and aposterior end 308. The end plate 300 has three pockets 310, placed onthe right lateral end 302, the left lateral end 304, and the anteriorend 306. The three pockets 310 are identical in shape and design, onlydiffering in placement on the end plate 300. Each pocket 310 has twoangled corners 312. If the implant: 14 is to be placed using theanterior approach, as depicted in FIG. 8, the end plate holder 200 willbe connected to the end plate 300 via the pocket 310 located on theanterior end 306. Similarly, if the implant 14 is to be placed using aright lateral approach, the end plate holder 200 will be connected viathe pocket 300 on the right end 302 and if the implant is to be placedusing a left lateral approach, the end plate holder 200 will beconnected via the pocket 310 in the left end 304.

The first end 250 of the end plate holder 200 comprises an expandableretention interface having two prongs 202. The two prongs 202 terminatein angled prong tips 204, which have radius edges 206. In the embodimentdepicted, the anterior approach is used, so the end plate holder 200 isconnected to the end plate 300 by placing the two prongs 202 into thepocket 310 on the anterior end 306. Once the prongs 202 are placed inthe pocket 310, the spreader 220 is extended lengthwise between the twoprongs 202, by lowering the lever 222 illustrated in FIG. 7. As thespreader 220 extends, the prong tips 204 are forced apart, and pushedinto the outer pocket corners 312. When the spreader 220 is fillyextended, the spreader tip 228 is pushed firmly against the end of thepocket 310, and the prong tips 204 are forced slightly back, thusseating their rounded edges 206 against the pocket corners 312. Thisseating creates a firm connection between the end plate 300 and the endplate holder 200. The second end plate 300 is connected to the first end250 of the second end plate holder 200 in an identical manner.

As seen in FIG. 8, each end plate 300 has a plurality of spikes 314. Thespikes 314 comprise hollow, pointed protrusions extending from anexterior surface 316 of the end plate 300. The spikes 314 are positionedsuch that they form a ring on the exterior surface 316, but are set backfrom the ends 302-308 of the end plate 300, allowing an outer ring offlat surface area between the spikes 314 and the ends 302-308.

After each of the end plates 300 is attached to the end plate holders200, a spike guard 400 is fitted over the exterior surface 316. As seenin FIG. 9, the distal end of each spike guard 400 terminates in a flat,spatula-like cover plate 402 that fits over the exterior surface 316 ofthe end plate 300. The inside of the cover plate 402 has grooves 404into which the centrally located spikes 314 slide as the spike guards400 are put on. The spike guards 400 are put on to the end plates 300 bysliding them distally parallel to the end plate holders 200 and onto theend plates, allowing the spikes 314 to slide into the grooves 404,illustrated in FIG. 10. The outer surface of the cover plate has twocurved notches 406 which come to rest around the spikes 314 nearest theright end 302 and left end 304 of the end plate 300. These two spikes314 are not covered, but the outer surface of the cover plate 402extends higher than the ends of the spikes 314, so the spikes 314 do notprotrude past the cover plate 402. The cover plate 402 prevents thespikes 314 from snagging or scratching anything prior to implantation,and prevents premature contact between the spikes 314 and the vertebralbodies. The spike guards 400 are composed of a radiolucent material, sothat the end plates 300 are visible through radiography during theimplantation process. Placement and removal of the spike guards 400 isvia handles (not visible in FIG. 9). The spike guard depicted in FIGS. 9and 10 is designed for use during an anterior approach implantation. Itis appreciated that the shape and placement of the spike guards maydiffer in alternative embodiments of the invention.

FIG. 11 depicts the distal end of a primary spacer 500. The distal endof the primary spacer 500 terminates in a flat, rectangular plate 502. Ashaft 504 connects the plate 502 to a handle at the proximal end (notvisible in FIG. 11). Raised edges 506 extend partway up the shaft 504from the plate 502 toward the proximal end The raised edges 506 have adistal end 508 near the plate 502 and a proximal end 510 partway up theshaft 504.

FIG. 12 illustrates the distal ends of the two end plate holders 200with attached end plates 300, spike guards 400, and one primary spacer500. Two primary spacers 500 are used in the procedure, but only one isillustrated so that the details of the end plate holder 200 may be seen.Either before or after the spike guards 400 are fitted over the endplates 300, the two primary spacers 500 are slid in between the endplate holders 200, as also shown in FIG. 5. The first primary spacer 500is slid parallel to the inner side of the end plate holder 200 such thatthe raised edges 506 clasp around the lateral edges of the end plateholder 200 and slide inside a lateral groove 212. When the distal end508 of the raised edge 506 contacts the end plate 300, the primaryspacer 500 is in place and cannot move distally any more. The plate 502is in between the two end plates 300. The other primary spacer 500 isslid into place next to the other end plate holder 200, and its plate502 comes to rest between the first plate 502 and the end plate 300. Theprimary spacers are radiolucent, so they do not obscure the visibilityof the end plates 300 and vertebral bodies during implantation. Thenumber and positioning of spacers may vary with alternative embodimentsof the invention.

The pivot assembly 18 and attached instrument assembly 16 are now readyto be positioned for the implantation procedure. Referring to FIGS. 2,and 4, the pivot assembly 18 is attached to the adjustable supportassembly 12 via one of the two support assembly balls 114. The supportassembly 12 is adjusted so that the pivot assembly 18 and the instrumentassembly 16 are supported over the patient in a position appropriate tothe approach chosen (anterior, right lateral, or left lateral). Theinstrument assembly 16 is positioned so that the end plates 300 coveredwith the protective spikes guards 400 are placed between the vertebralbodies. Radiography is employed to observe the positioning of the endplates. At this point, the surgical personnel select the components ofthe disc implant 14. The radiolucent spike guards 400 allow the surgicalpersonnel to see the end plates 300 in position relative to thevertebral bodies, and the personnel can determine which size, thicknessand angle of bearings 800, 850 should be used.

FIG. 13 displays an exploded side view of disc implant 14. The superiorbearing 800 has a superior bearing surface 802 in which is an indentedcup 810. The inferior bearing 850 has an inferior bearing surface 852,from which protrudes a dome 860. When the bearings 800, 850 are held inplace between the two end plates 300, the cup 810 fits over the dome860, and the superior bearing surface 802 is in contact with theinferior bearing surface 852. The snap fasteners 900 connect thebearings 800, 850 to the end plates 300 by fitting into snap ports 330on the end plates 300, and into troughs 804, 854 on the bearings 800,850.

All pieces—end plates 300, the inferior bearing 850, the superiorbearing 800 and the snap fasteners 900 are made in three sizes, wheresize refers to the area of the component, which will correspond to thearea of the vertebral bodies where the disc implants are implanted. Thesuperior bearings 800 are made in a variety of thicknesses, to match theheight of the intervertebral space. The inferior bearings 850 are madein a variety of angles, in which the height of the posterior end of theinferior bearing is greater than the height of the anterior end of theinferior bearing, to match the angle of the intervertebral space. Ifdeemed necessary, the end plates 300 can be removed and alternate,differently sized end plates 300 substituted for them.

Referring back to FIG. 6, the adjustment screws 160, 120 on the guidearms 156, 116 allow for height and angle adjustment control at thesecond ends 260 of the end plate holders 200 while the first ends 250are inserted in the intervertebral space. The height adjustment screw160 at the second end 260 of the end plate holder 200 can be turned ineither direction, raising or lowering the first end 250 of the end plateholder 200, until the end plate 300 is correctly positioned in theintervertebral space. The height measurement gauge 170 is read on theheight adjustment guide arm 156 and the superior bearing 800 matchingthat height is selected. Similarly, the angle adjustment screw 120 atthe second end 260 of the other end plate holder 200 can be turned,changing the anterior-posterior angle of the first end 250 of the otherend plate holder 200, until the end plate 300 is correctly positioned.The angle measurement gauge 130 is read on the angle adjustment guidearm 116 and the inferior bearing 850 matching that angle is selected.

An alternate method for determining the correct size of end plates 300and bearings is to have a group of samples which duplicate the size,thickness and angles of the end plates and bearings. These samplecomponents are each mounted on a shaft to allow temporary insertion intothe intervertebral space, to determine if the size, thickness and angleof the components are correct. A sample has the same dimensions as thetwo end plates, the inferior and superior bearings, and the snapfittings do when they are fitted together as they would be in theintervertebral space. Instead of temporarily inserting and removing theactual end plates and bearings to check for the proper configuration,the samples can be inserted and removed to determine the proper choicefor each component.

Once the correct disc implant 14 components are chosen, the finalposition of the end plates 300 is adjusted. Radiography is used to seewhere the end plates 300 and more specifically the spikes 314 will fitagainst the vertebral bodies. The angle adjustment screw 120 is turnedto place the end plate holder 200 and end plate 300 at the proper angle.The height adjustment screw 160 is turned to raise or lower the otherend plate holder 200 and end plate 300. Once the correct angle andheight are determined, the adjustment knob 126 is tightened to lock theangle adjustment guide arm 116 in place, and the adjustment knob 166 istightened to lock the height adjustment guide arm 156 in place.

With the end plate holders 200 now locked in place at the correct heightand angle, the spike guards 400 are removed, allowing the now exposedspikes, 314 to engage against the surface of the vertebral bodies.Secondary spacers 550 are inserted between the primary spacers 500. Thisaction pushes the end plates 300 cephalic-caudally away from oneanother, and presses the spikes 314 into the vertebral bodies. FIG. 14illustrates the distal end of an individual secondary spacer 550. Thesecondary spacer 550 terminates in a paddle-like plate 552 that isthicker than the plate 502 of the primary spacer 500. A shaft 554connects the plate 552 to a handle (not visible in FIG. 14). Partway upthe shaft 554 in a proximal direction from the plate 552, a pair ofrails 556 are on either side of the shaft 554. The rails 556 havesquared edges 558 which extend out from the shaft 554.

FIG. 15 illustrates the distal end of instrument assembly 16, includingend plate holders 200, and primary and secondary spacers 500, 550. Theend plate holders 200 are holding two end plates 300. The secondaryspacers 550 are inserted one at a time into the space between the twoprimary spacers 500. As the secondary spacer 550 is moved into place,the edges 558 of the rails 556 slide into the lateral grooves 212 on theend plate holder 200. The secondary spacer 550 is slid distally untilthe rails 556 contact a proximal end 510 of the raised edges 506 of theprimary spacer 500, preventing the secondary spacer 550 from sliding anyfurther. The plate 552 is now positioned next to the plate 502 of theprimary spacer 500, and the primary spacer 500 is sandwiched between theend plate holder 200 and the secondary spacer 500. The other secondaryspacer 550 is inserted in the same fashion onto the opposite primaryspacer 500 and end plate holder 200. The action of inserting thesecondary spacers 550 pushes the spikes 314 into the vertebral bodies,thus firmly seating the exterior surfaces 316 of the end plates 300against the surface of the vertebral bodies.

With the end plates 300 implanted in the vertebral bodies, the primaryspacers 500 and secondary spacers 550 are removed. Removal isaccomplished by grasping the handles of the spacers 500, 550 and pullingthem proximally until they are free of the instrument assembly 16.

Referring back to FIG. 3, the bearing instrument assembly 17 used toplace the bearings 800, 850 between the implanted end plates 200 isdepicted. This assembly is supported by the pivot assembly 18, andcomprises the end plate holders 200, an angle compressor 650, a heightcompressor 600, and a bearing holder 700. At the distal end of theinstrumentation set is the intervertebral disc motion preservationimplant 14, which comprises the two end plates 300, an inferior bearing800, a superior bearing 850, and two snap fasteners 900, as illustratedin FIG. 10. The instruments which comprise instrument assembly 17 areassembled in the following order: the angle compressor 650 is insertedbetween the end plate holders 200; the bearings 800, 850 are attached tothe bearing holder 700; the height compressor 600 is attached to thebearing holder 700; and the bearing holder 700 (with attached heightcompressor 600 and bearings 800, 850) is inserted between the end plateholders 200.

FIG. 16 depicts the distal end of one angle compressor 650 with one endplate holder 200 and one end plate 300. The angle compressor 650 iscomprised of a handle at the proximal end (not visible in FIG. 14), ashaft 654, and two prongs 652. The shaft 654 has raised edges 658 whichextend perpendicularly from the shaft 654 and bend to form an L-shape.At the distal end of the shaft 654 are the prongs 652 which eachterminate in an angled ramp 662. Partway up the shaft 654 in a proximaldirection are a pair of rails 656. The L-shaped rails 656 extend in theopposite direction from the raised edges 658. The angle compressor 650is slid onto the end plate holder 200 which is attached to the angleguide arm 116 as seen in FIG. 6. The raised edges 658 slide into thelateral grooves 212 on either side of the end plate holder 200. Theangle compressor 650 is slid distally down the length of the end plateholder 200 until the distal ends 660 of the raised edges 658 contact theend plate 300. The prongs 652 lie on either side of the snap port 330 ofthe end plate 300.

The inferior side of the distal end of bearing holder 700 is illustratedin FIG. 17. The bearing holder 700 has two handles 734 at the proximalend (visible in FIG. 3), and a shaft 704 which terminates at its distalend all an intersection with a body 710. Along each lateral side of theshaft 704 is a camming channel 730 with undulating edges 732. The body710 extends distally and splits into two prongs 702. The body 710 andprongs 702 are generally flat and fork-like in shape, with a superiorside 716 and an inferior side 718. Where the body 710 originates at thebase of the shaft 704 are two shoulders 706, one on each lateral side ofthe shaft 704. Each shoulder 706 extends perpendicularly from the body710 in both directions. On each side of each shoulder is a slot 708which lies parallel to the prongs 702 and is open to the inside of theshoulder 706 adjacent to the shaft 704. At the base of each shoulder706, and between the slot 708, and the body 710, is a slanted edge 720.

Where the two prongs 702 meet at the base of the body 710 is a lockingkey 712 with two teeth 728. The locking key 712 is mounted on the end ofa pin 722 that extends from the proximal end of the shaft to the distalend, and is enclosed in a channel 724. At the proximal end of thebearing holder 700, the pin 722 emerges from the channel 724 and iscapped by an adjustment nut 726 (seen in FIG. 3). When the adjustmentnut 726 is turned, the pin 722 and the locking key 712 turn.

FIG. 18 depicts a superior side view of superior bearing 800 and aninferior bearing 850 mounted on the bearing holder 700. In theembodiment depicted, the bearings 800, 850 are mounted in the anteriorposition; however they can also be mounted in either of the lateralpositions, depending upon which surgical approach is used. Prior tomounting, the snap fasteners 900 are snapped onto the bearings 800, 850.The superior bearing 800 is mounted on the superior side 716 of thebearing holder 700. The superior bearing 800 is placed parallel to andadjacent to the body 710, with the cup 810 surrounded by the prongs 702.Anterior faceted edges 806 of the superior bearing 800 are flush againstthe slanted edges 720 of the shoulders 706. One tooth 728 of the lockingkey 712 protrudes into the anterior instrument port 816. Simultaneously,the inferior bearing 850 is placed on the inferior side 718 of thebearing holder 700, parallel to and adjacent to the body 710 and withthe prongs 702 surrounding the dome 860. Anterior faceted edges 856 ofthe inferior bearing 850 are flush against the slanted edges 720 of theshoulders 706, and the other tooth 723 of the locking key 712 isprotruding through the anterior instrument port 866. With both bearings800, 850 held thus, the adjustment nut 726 is turned. The pin 722 andlocking key 712 turn, and the teeth 728 on the locking key 712 engageand tighten down on the edges of the instrument ports 816, 866. Thebearings 800, 850 are thus locked in place on the bearing holder 700.The inferior bearing surface 852 and the superior bearing surface 802are adjacent to one another, with the dome 860 encircled by the cup 810(not visible in FIG. 18).

FIG. 19 illustrates the distal end of the height compressor 600. At theproximal end is a handle (not visible in FIG. 19). The height compressor600 has a shaft 604 with two prongs 602 at its distal end 610. Eachprong 602 terminates in an angled ramp 612. On either lateral side ofthe shaft 604 is a raised edge 608, which extends perpendicularly fromthe shaft 604 and bends to form an L-shape. Slightly above the distalend 610 of the shaft 604 is a pair of rails 606, with one rail 606located on each raised edge 608. A second pair of rails 606 is locatedsome distance proximally along the shaft 604, one on each raised edge608.

The bearing holder 700 with attached bearings 800, 850, and a heightcompressor 600 are shown in FIG. 20. The height compressor 600 isconnected to the bearing holder 700 by sliding the height compressor 600parallel to the bearing holder 700 in the distal direction, on thesuperior side 716, allowing the rails 606 to clasp the camming channel730 on each side of the bearing holder 700. As the height compressor 600slides, the prongs 602 slide into the slots 708 on the bearing holder700. The height compressor 600 is slid distally until the rails 606contact the shoulders 706 of the bearing holder 700. At this point theheight compressor 600 cannot slide distally any farther and the prongs602 encircle the snap fastener 900 on the superior bearing 800. Theraised edges 608 are facing outward.

After the height compressor 600 is connected to the bearing holder 700,these two instruments and the attached bearings 800, 850 are inserted asa set between the end plate holders 200, as seen in FIG. 3. The anglecompressor 650 is already in place, connected to one end plate holder200, as seen in FIG. 16. The distal ends of the bearing holder 700 andthe height compressor 600, with the attached bearings 800, 850 areinserted between the end plate holders 200, oriented so that the heightcompressor 600 is slid in next to the end plate holder 200 which issuspended from the height adjustment arm 156 (seen in FIG. 6).The heightcompressor 600, bearing holder 700 and bearings 800, 850 are slid in adistal direction parallel to the end plate holders 200. As theinstruments are slid in, the rails 656 of the angle compressor 650 slideinto the camming channels 730 on the bearing holder 700, and the prongs652 slide into the slots 708. Simultaneously, the raised edges 608 ofthe height compressor 600 clasp the lateral grooves 212 of the end plateholder 200. The instrument set is slid distally until the shoulders 706of the bearing holder 700 contact the end plates 300. At this point, theinstrument set cannot slide in any farther and the prongs 652 of theangle compressor 650 encircle the snap fastener 900 between the endplate 300 and the inferior bearing 850.

All components of the intervertebral disc motion preservation implant 14are now in position between the vertebral bodies. FIG. 211 illustratesthe implant 14 held in place by the end plate holders 200 and bearingholder 700. To attach the bearings 800, 850 to the end plates 200 theheight and angle compressors 600, 650 are removed, one at a time, ineither order. The height compressor 600 is removed by grasping thehandle and pulling it proximally. As the height compressor 600 slidesout, the rails 606 slide proximally along the camming channels 730 ofthe bearing holder 700. As the height compressor 600 is removed, theprongs 602 are slid out from between the end plate 300 and the superiorbearing 800. Just when the prongs 602 reach the point where they are nolonger between the end plate 300 and the superior bearing 800, the rails606 slide over a widening in the undulating edges 732 of the cammingchannels 730. This forces the bearing holder 700 slightly closer tocompressor 600, and therefore closer to the end plate holder 200. Sincethe prongs 602 of the height compressor 600 are no longer between theend plate 200 and the superior bearing 800, the additional force snapsthe snap fastener 900 on the bearing 800 into place in the snap port 330on the end plate 200.

The angle compressor 650 is removed in the same way. The anglecompressor 650 is removed by grasping the handle and pulling itproximally. As the angle compressor 650 slides out, the rails 656 slideproximally along the camming channels 730 of the bearing holder 700. Asthe angle compressor 650 is removed, the prongs 652 are slid out frombetween the end plate 300 and the inferior bearing 850. Just when theprongs 652 reach the point where they are no longer between the endplate 300 and the inferior bearing 850, the rails 656 slide over awidening in the undulating edges 732 of the camming channels 730. Thisforces the bearing holder 700 slightly closer to compressor 650, andtherefore closer to the end plate holder 200. Since the prongs 652 ofthe angle compressor 650 are no longer between the end plate 200 and theinferior bearing 850, the additional force snaps the snap fastener 900on the bearing 850 into place in the snap port 330 on the end plate 200.The adjustment null. 726 on the bearing holder 700 is turned, so theteeth 728 disengage from the instrument ports 816, 866. All componentsof the intervertebral implant 14 are now in place between the end plates200.

Referring to FIGS. 3 and 8, the bearing holder 700 is removed bygrasping its handles 734 and pulling it proximally between the end plateholders 200 until it is free of the end plate holders 200 and the pivotassembly 18. Each end plate holder 200 is disengaged from its end plate300 by raising the lever 222. Raising the lever 222 retracts thespreader 220, and the prongs 202 are loosened within the pocket 310. Theend plate holder 200 can now be removed by pulling it proximally awayfrom the end plate 200. Thus all of the instrument assembly 17 isremoved from the patient.

Should removal of the implant 14 or replacement of any of itsconstituent components be required, such procedure may be carried out inany of the three approaches; anterior, right lateral, or left lateral,regardless of which approach was used during the initial implantation.To remove any component, first each end plate holder 200 is connected tothe pivot assembly 18, as seen in FIG. 6, with the lever 222 in thelowered position. The prongs 202 are guided into the pocket 310 of theend plate 300, and the lever 222 is raised. The spreader 220 movesdistally, and the prongs 202 are spread into the pocket corners 312.With the end plate holders 200 now connected to the end plates 300, thebearing holder 700 is inserted between the end plate holders 200, Thebearing holder 700 is oriented so that the superior side 716 is facingthe end plate holder 200 which is connected to the height adjustmentguide arm 156, and the inferior side 718 is facing the end plate holder200 which is connected to the angle adjustment guide arm 116. As thebearing holder 700 is inserted, the prongs 702 will slide between thebearings 800, 850 such that the prongs 702 lie on either side of thedome 860. When the prongs 702 are in place, the adjustment nut 726 isturned, so that the teeth 728 engage in the instrument ports 816, 866,and the bearings 800, 850 are locked to the bearing holder 700.

Next, the compressors 600, 650 are inserted in either order. The heightcompressor 600 is slid distally along the end plate holder 200 which isconnected to the height adjustment guide arm 156, so that the raisededges 608 slide into and along the lateral groove 212. As the compressoris slid distally along the end plate holder, the rails 606 slide overthe undulating edges 732 and into the camming channel 730. When theramps 612 on the prongs 602 slide in between the end plate 300 and thesuperior bearing 800, their intrusion will pry the snap fastener 900apart from the snap port 330. The angle compressor 650 is then sliddistally along the end plate holder 200 which is connected to the angleadjustment guide arm 116, so that the raised edges 658 slide into andalong the lateral groove 212, and the rails 656 slide along the cammingchannel 730. When the ramps 662 on the prongs 652 slide in between theend plate 300 and the inferior bearing 850, their intrusion will pry thesnap fastener 900 apart from the snap port 330.

The bearings 800, 850 are now free from the end plates 300, and attachedto the bearing holder 700. The bearing holder 700 with the attachedhearings 800, 850, and the compressors 600, 650 are removedsimultaneously, by grasping their handles and pulling them proximallyout from between the end plate holders 200. At this juncture newbearings 800, 850 may be inserted in the same manner as describedpreviously.

An alternative embodiment of the invention is illustrated in FIGS.22-33. This embodiment uses many of the same instruments as describedfor the previous embodiment, and is configured to implant the implant14, a fusion block, or an alternative implant. The alternativeembodiment comprises alternative bearing placement guidanceinstrumentation, and compression instrumentation.

Referring to FIG. 22, the support assembly 12, pivot assembly 18 and endplate assembly 16 are shown with an alternative bearing guidanceassembly 1017, an alternative implant 1014, and a compressor 1600. Thebearing guidance assembly 1017 comprises a bearing holder 1700 withguidance features. The implant 1014 comprises two end plates 1300, asuperior bearing 1800, an inferior bearing 1850, and two snap fasteners1900. The bearing holder 1700 holds and guides the superior and inferiorbearings 1800, 1850 as they are inserted between the end plates 1300.The compressor 1600 provides compressive force to the end plates 1300,pushing them toward the bearings 1800, 1850 causing the snap fasteners1900 to engage to the end plates 1300, thus connecting the end plates1300 to the bearings 1800, 1850. The compression instrumentation alsoincludes feeler gauges (not shown in FIG. 22) which test the snapfastener connection. Although the alternative implant 1014 is depictedin FIGS. 22-28, the alternative bearing guidance assembly 1017 couldalso be used to place the implant 14, or a fusion block.

Referring to FIG. 23, an enlarged exploded view of the alternative discmotion preservation implant 1014 is depicted. Each end plate 1300 has asnap port 1330. The superior bearing 1800 has a trough 1804 on itssuperior side, and the inferior bearing 1850 has a trough 1854 on itsinferior side. The snap fasteners 1900 connect the end plates to thesuperior and inferior bearings when all components of the implant aresnapped together. Prior to implantation, one snap fastener 1900 issnapped into the trough 1804 on the superior bearing 1800, and similarlythe second snap fastener 1900 is snapped into the trough 1854 on theinferior bearing 1850.

FIG. 24 depicts the bearing holder 1700, holding the superior andinferior bearings 1800, 1850. A snap fitting 1900 is attached to eachbearing 1800, 1850. The superior bearing 1800 is held on a superior side1716 of the bearing holder 1700, and the inferior bearing 1850 is heldon an inferior side 1718. The bearing holder 1700 has two handles 1734at the proximal end, and a shaft 1704 which terminates at its distal endat an intersection with a body 1710. Along a portion of each lateralside of the shaft 1704 is guide rail 1730, which extend perpendicularlyfrom the shaft 1704 on the inferior side 1718. Near the distal end ofthe shaft 1704, a pair of slider arms 1732 extends from the superiorside 1716, holding a slider link 1736. An inferior feeler gauge 2050 isslidably engaged on the shaft 1704 of the bearing holder 1700.

Referring to FIG. 25, an enlarged view of the inferior side 1718 ofdistal end of the bearing holder 1700 is shown. At the end of the shaft1704, the body 1710 extends distally and splits into two prongs 1702.The body 1710 and prongs 1702 are generally flat and fork-like in shape.Where the body 1710 originates at the base of the shaft 1704 are twostops 1708, one on each lateral side of the shaft 1704, which protrudeperpendicularly from the shaft on the inferior side 1718. Distal fromthe stops 1708, where the two prongs 1702 extend from the body 1710, aretwo shoulders 1706, one on each lateral side of the body 1710. Eachshoulder 1706 extends perpendicularly from the body 1710 in bothsuperior 1716 and inferior 1718 directions.

Where the two prongs 1702 meet at the base of the body 1710 is a lockingkey 1712 with two teeth 1728. The locking key 1712 is mounted on the endof a pin 1722 that extends from the proximal end of the shaft to thedistal end, and is enclosed in a channel 1724. At the proximal end ofthe bearing holder 1700, the pin 1722 emerges from the channel 1724 andis capped by an adjustment nut 1726 (seen in FIG. 23). When theadjustment nut 1726 is turned, the pin 1722 and the locking key 1712turn.

Referring to FIG. 26, an enlarged view of the superior side 1716 of thedistal end of the bearing holder is shown. Just proximal to the body1710, a slider arm 1732 is linked to each side of the shaft 1704.Extending between the ends of the arms 1732 is the slider link 1736,which has a guide rail 1740 at each of its lateral ends. The guide rails1740 are configured to grip the lateral edges of the end plate holders1200 as the bearings 1800, 1850 are inserted or withdrawn, thus guidingthe bearings in between the end plates 1300.

Referring to FIG. 27, an enlarged view shows the bearings 1800, 1850mounted on the distal end of the bearing holder 1700. The bearings 1800,1850 are mounted on the bearing holder 1700 in the same manner asdescribed previously for the bearings 800, 850 and the bearing holder700.

Referring to FIG. 28, the bearing holder 1700 with mounted bearings1800, 1850 is shown inserted between the end plate holders 200 and theend plates 1300. The bearing holder 1700 and bearings 1800, 1850 areslid in between the proximal ends of end plate holders 200 as they areheld in the pivot assembly 18. As the bearing holder 1700 is sliddistally, the guide rails 1730 are maneuvered so that they clasp theedges of the inferior end plate holder 200. Similarly, the guide rails1740 clasp the edges of the superior end plate holder 200. With theguide rails 1730, 1740 thus engaged, the bearings 1800, 1850 are able toslide in between the end plates 1200 with a minimum of lateral movementand adjustment. When the bearings 1800, 1850 reach the end plates 1200,the shoulders 1706 of the bearing holder 1700 contact the end plates1300, preventing any further distal movement, and lining the bearings1800, 1850 up so that the snap fasteners 1900 will correctly engage withthe end plates 1300 when compressed.

Referring to FIG. 29, a compressor 1600 is shown. The compressor 1600has a handle 1602, a compression lever 1604, a shaft 1606 and at thedistal end of the shaft 1606, a pair of tongs 1608. When the compressor1600 is implemented, the tongs 1608 push the end plates 1300 toward thebearings 1800, 1850, providing force so the snap fasteners 1900 snapinto the snap ports 1330 on the end plates 1300.

Referring to FIG. 30, an enlarged view of the distal end of thecompressor 1600 is shown. Extending lengthwise along the shaft 1606 is apull bar 1610, which is pivotably connected at its proximal end to thecompression lever 1604, and is pivotably connected at its distal end tothe tongs 1608. The tongs 1608 are pivotably connected to a pair ofcross links 1612, which are pivotably connected to the distal end of theshaft 1606. When the compression lever 1604 is pulled toward the handle1602, the pull bar 1610 moves distally parallel to the shaft 1606, andthe tongs 1608 are forced together.

Returning to FIG. 22, the end plate assembly 16 and the bearing guidanceassembly 1017 are shown, with the compressor 1600 grasping the end plateholders 200. The compressor 1600 is placed so that each tong 1608 isadjacent to the shaft 201 of each end plate holder 200. The compressionlever 1604 is raised, thus extending the pull bar 1610 and pulling thetongs 1608 together, which push the end plate holders 200 with theattached end plates 1300 together. The snap fasteners 1900, which arealready engaged in the troughs on the bearings 1800, 1850, are pushedinto the snap ports 1330 on the end plates 1300.

Referring to FIG. 31, a superior feeler gauge 2000 is shown. Thesuperior feeler gauge 2000 has a handle 2002 and a wide shaft 2004 withguide rails 2006 on each lateral side of the shaft 2004. The shaft 2004terminates at a tang 2008 which extends distally from the distal end ofthe shaft 2004.

Referring to FIG. 32, the inferior feeler gauge 2050 is shown. Theinferior feeler gauge 2050 has a handle 2052, a shaft 2054, and a body2060. Guide rails 2056 line each lateral edge of the body 2060, and theyenable the gauge 2050 to be slidably engaged to the bearing holder 1700.At the distal end of the body 2060, a tang 2058 extends distally fromthe body 2060.

The feeler gauges 2000, 2050 are used to test if the snap fasteners 1900have properly snapped to the end plates 1300 following compression. Thecompressor 1600 is removed from the instrument assembly 1017, and thesuperior feeler gauge 2000 is inserted between the end plate holders 200and the bearing holder 1700. The inferior feeler gauge 2050 is alreadyengaged on the bearing holder 1700, as seen in FIG. 24. The superiorfeeler gauge 2000 is inserted on the superior side 1716 of the bearingholder 1700, so that its guide rails 2006 clasp the edges of thesuperior bearing holder 200. The gauge 2000 is slid distally until itstang 2008 slides in between the superior end plate 1300 and the superiorbearing 1800. If the snap connection between the end plate 1300 and thebearing 1800 has been successfully made, the tang 2008 will not be ableto slide between the snap fastener 1900 and the end plate 1300. If,however, the snap fastener 1900 has failed to engage with the snap port1330 on the end plate 1300, the tang 2008 will continue to slidedistally until it lies between the snap fastener 1900 and the end plate1300.

Similarly, the inferior feeler gauge 2050 is slid distally until itstang 2058 slides in between the inferior end plate 1300 and the inferiorbearing 1850. If the snap connection between the end plate 1300 and thebearing 1850 has been successfully made, the tang 2058 will not be ableto slide between the snap fastener 1900 and the end plate 1300. If,however, the snap fastener 1900 has failed to engage with the snap port1330 on the end plate 1300, the tang 2058 will continue to slidedistally until it lies between the snap fastener 1900 and the end plate1300.

If either snap fastener 1900 has failed to engage with its correspondingend plate 1300, the feeler gauges 2000, 2050 are slid proximally, andthe compressor 1600 is realigned with the end plate holders 200.Compression is again attempted, and re-tested with the feeler gaugesuntil both snap fasteners 1900 are snapped in place on the end plates1300.

Referring to FIG. 33, a fusion block 2100 is shown attached to thedistal end of the bearing holder 1700. When fusion instead of motionpreservation is desired, the fusion block 2100 may be inserted inbetween two end plates 1300 in the intervertebral space, using the samebearing delivery methods as described previously. The fusion block 2100,with two snap fasteners 1900 snapped onto each of its two snap ports2130, is locked on the end of the bearing holder 1700 using the lockingkey 1712 mechanism. The fusion block 2100 and snap fasteners 1900 areinserted between the end plates 1300, and snapped to the end plates 1300using the compressor 1600.

It is appreciated that the bearing set 1800, 1850 and the fusion block2100 are interchangeable, using the same instrumentation andimplantation methods. If a motion preservation implant has beenimplanted, but a change to fusion is desired, the patient may bereopened, and the original implant removed with the instrumentationdescribed above. A fusion block may then be implanted with the sameinstrumentation. If fusion is to be replaced with a motion preservationimplant, the procedure may be reversed. It is also appreciated that allprocedures described above may be carried out from an anterior approach,a right lateral approach, or a left lateral approach. Scar tissuebuildup may be reduced by carrying out any revisions by a differentapproach, e.g., original implantation from an anterior approach andrevision from a left or right lateral approach, or vice versa.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. It isappreciated that various features of the above-described examples can bemixed and matched to form a variety of other alternatives. As such, thedescribed embodiments are to be considered in all respects only asillustrative and not restrictive. The scope of the invention is,therefore, indicated by the appended claims rather than by the foregoingdescription. All changes which come within the meaning and range ofequivalency of the claims are to be embraced within their scope.

1. An intervertebral implant delivery system comprising: a first endplate holder comprising a first end and a second end; a second end plateholder comprising a first end and a second end; and a pivot assemblythat couples the first and second end plate holders together; whereineach of the first ends is shaped to retain an end plate of anintervertebral implant to facilitate insertion of the end plate into anintervertebral space; wherein the pivot assembly is configured to permitactuation of the second ends while the first ends are in theintervertebral space to permit adjustment of a thickness and anangulation of a space between the end plates.
 2. The intervertebralimplant delivery system of claim 1, wherein the angulation comprises ananterior-posterior angulation, wherein the end plate holder isadjustable interoperatively from a lateral approach to determine theangulation.
 3. The intervertebral implant delivery system of claim 1,wherein at least one of the first end plate holder, the second end plateholder, and the pivot assembly comprises a support feature attachable toa stationary frame to keep the pivot assembly substantially stationary.4. The intervertebral implant delivery system of claim 3, furthercomprising the stationary frame, wherein the support feature comprises aball extending from the pivot assembly to permit polyaxial positioningof the pivot assembly relative to the stationary frame.
 5. Theintervertebral implant delivery system of claim 1, further comprising aspike guard shaped to protect a first vertebral body adjacent to theintervertebral space from contact with at least one spike extending fromthe intervertebral implant.
 6. The intervertebral implant deliverysystem of claim 1, further comprising a first spacer insertable betweenthe first and second end plate holders to urge the end plates towardfirst and second vertebral bodies, respectively, wherein the first andsecond vertebral bodies bound the intervertebral space.
 7. Theintervertebral implant delivery system of claim 6, further comprising asecond spacer insertable between the first and second end plate holdersto further urge the end plates toward the first and second vertebralbodies.
 8. The intervertebral implant delivery system of claim 1,further comprising an intermediate component holder configured to hold afirst intermediate component and to facilitate insertion of the firstintermediate component into the space between the end plates.
 9. Theintervertebral implant delivery system of claim 9, wherein the firstintermediate component comprises a first articulating bearing, whereinthe intermediate component holder is further configured to hold a secondarticulating bearing and to retain the first and second articulatingbearings for simultaneous insertion into the space between the endplates.
 10. The intervertebral implant delivery system of claim 1,further comprising a compressor configured to be actuated to urge theend plates together to cause the end plates to snap into engagement withone or more intermediate components positioned between the end plates.11. An intervertebral implant delivery system comprising: a first endplate holder configured to deliver a first end plate to anintervertebral space from any approach selected from the groupconsisting of an anterior approach and a lateral approach; and anintermediate component holder configured to deliver a first intermediatecomponent securable to the first end plate to the intervertebral spacefrom any approach selected from the group consisting of an anteriorapproach and a lateral approach.
 12. The intervertebral implant deliverysystem of claim 11, further comprising a support feature attachable to astationary frame to keep the pivot assembly substantially stationary.13. The intervertebral implant delivery system of claim 1, furthercomprising: a second end plate holder configured to deliver a second endplate to the intervertebral space; and a first spacer insertable betweenthe first and second end plate holders to urge the end plates towardfirst and second vertebral bodies, respectively, wherein the first andsecond vertebral bodies bound the intervertebral space.
 14. Theintervertebral implant delivery system of claim 11, wherein the firstintermediate component comprises a first articulating bearing, whereinthe intermediate component holder is further configured to hold a secondarticulating bearing and to retain the first and second articulatingbearings for simultaneous insertion into the intervertebral space. 15.The intervertebral implant delivery system of claim 11, wherein thefirst end plate holder comprises a first end comprising an expandableretention interface configured to engage any of a plurality of slots ona periphery of the first end plate to couple the first end plate to thefirst end.
 16. An intervertebral implant delivery system comprising: afirst end plate holder configured to deliver a first end plate to anintervertebral space; a second end plate holder configured to deliver asecond end plate to the intervertebral space; and an intermediatecomponent holder configured to deliver first and second articulatingbearings to the intervertebral space simultaneously and independently ofdelivery of the first and second end plates to the intervertebral space.17. The intervertebral implant delivery system of claim 16, wherein thefirst end plate holder, second end plate holder, and intermediatecomponent are configured to deliver the first and second articulatingbearing surfaces while holding the first and second end platessubstantially stationary.
 18. The intervertebral implant delivery systemof claim 16, further comprising a pivot assembly that couples the firstand second end plate holders together, wherein at least one of the firstend plate holder, the second end plate holder, and the pivot assemblycomprises a support feature attachable to a stationary frame to keep thepivot assembly substantially stationary.
 19. The intervertebral implantdelivery system of claim 16, further comprising a first spacerinsertable between the first and second end plate holders to urge theend plates toward first and second vertebral bodies, respectively,wherein the first and second vertebral bodies bound the intervertebralspace.
 20. The intervertebral implant delivery system of claim 16,wherein the intermediate component holder is configured to deliver thefirst and second articulating bearings to the intervertebral space fromany approach selected from the group consisting of an anterior approachand a lateral approach.
 21. An intervertebral implant delivery systemcomprising: a compression instrument comprising a first end and a secondend; wherein, in response to actuation of the second end, the first endexerts compressive force in a cephalad-caudal direction on first andsecond end plates of an intervertebral implant within an intervertebralspace to secure the end plates to an intermediate component positionedbetween the end plates.
 22. The intervertebral implant delivery systemof claim 21, wherein the end plates are configured to be anchored tofirst and second vertebral bodies bounding the intervertebral space;wherein the first end is configured to exert the compressive force onthe end plates without removing the end plates from anchorage to thefirst and second vertebral bodies.
 23. The intervertebral implantdelivery system of claim 21, wherein the first end comprises a pair oftongs; wherein the second end comprises a handle and a compression leverthat is movable by hand relative to the handle to urge the tongs to movetoward each other.
 24. The intervertebral implant delivery system ofclaim 21, further comprising: a first end plate holder configured todeliver the first end plate to an intervertebral space; a second endplate holder configured to deliver the second end plate to theintervertebral space; and a pivot assembly that couples the first andsecond end plate holders together.
 25. The intervertebral implantdelivery system of claim 24, further comprising an intermediatecomponent holder configured to deliver a first intermediate componentsecurable to the end plates to the intervertebral space.
 26. Anintervertebral implant delivery system comprising: a removal instrumentcomprising a first end and a second end; wherein, in response toactuation of the second end, the first end exerts force in acephalad-caudal direction on first and second end plates of anintervertebral implant within an intervertebral space to detach anintermediate component from the first and second end plates.
 27. Theintervertebral implant delivery system of claim 26, wherein the endplates are configured to be anchored to first and second vertebralbodies bounding the intervertebral space; wherein the first end isconfigured to exert the force on the end plates without removing the endplates from anchorage to the first and second vertebral bodies.
 28. Theintervertebral implant delivery system of claim 26, wherein the secondend comprises a handle and the first end comprises a pair of prongsshaped to slide between the end plates to pry the end plates apart. 29.The intervertebral implant delivery system of claim 26, furthercomprising: a first end plate holder configured to deliver the first endplate to an intervertebral space; a second end plate holder configuredto deliver the second end plate to the intervertebral space; and a pivotassembly that couples the first and second end plate holders together.30. The intervertebral implant delivery system of claim 29, furthercomprising an intermediate component holder configured to deliver afirst intermediate component securable to the end plates to theintervertebral space.
 31. A method for delivering an intervertebralimplant, the method comprising: retaining a first end plate of anintervertebral implant with a first end of a first end plate holder;retaining a second end plate of the intervertebral implant with a firstend of a second end plate holder coupled to the first end plate holderby a pivot assembly; inserting the first end plate into anintervertebral space; inserting the second end plate into theintervertebral space; and actuating second ends of the first and secondend plate holders to adjust at least one of a thickness and anangulation of a space between the end plates.
 32. The method of claim31, wherein the angulation comprises an anterior-posterior angulation,wherein actuating the second ends comprises actuating the second endsfrom a lateral approach to determine the angulation.
 33. The method ofclaim 31, further comprising attaching at least one of the first endplate holder, the second end plate holder, and the pivot assembly to astationary frame to keep the pivot assembly substantially stationary.34. The method of claim 31, further comprising inserting a first spacerbetween the first and second end plate holders to urge the end platestoward first and second vertebral bodies, respectively, wherein thefirst and second vertebral bodies bound the intervertebral space. 35.The method of claim 31, further comprising: retaining a firstintermediate component with an intermediate component holder, andinserting the first intermediate component into the space between theend plates.
 36. The method of claim 35, wherein inserting theintermediate component into the space between the end plates comprises:selecting an approach from the group consisting of a lateral approachand an anterior approach; and inserting the first intermediate componentinto the space along the selected approach.
 37. The method of claim 35,further comprising: detaching a second intermediate component from thefirst and second end plates; and removing the second intermediatecomponent from the space prior to insertion of the first intermediatecomponent into the space.